Make UserActivityDetector a singleton

BUG=426561,408752
TEST=None

Review URL: https://codereview.chromium.org/693643004

Cr-Commit-Position: refs/heads/master@{#302734}

ash/display/display_change_observer_chromeos.cc

@@ -267,7 +267,7 @@ void DisplayChangeObserver::OnDisplayModeChanged(
   // For the purposes of user activity detection, ignore synthetic mouse events
   // that are triggered by screen resizes: http://crbug.com/360634
   ::wm::UserActivityDetector* user_activity_detector =
-      Shell::GetInstance()->user_activity_detector();
+      ::wm::UserActivityDetector::Get();
   if (user_activity_detector)
     user_activity_detector->OnDisplayPowerChanging();
 }

ash/shell.h

@@ -368,9 +368,6 @@ class ASH_EXPORT Shell : public SystemModalContainerEventFilterDelegate,
   MruWindowTracker* mru_window_tracker() {
     return mru_window_tracker_.get();
   }
-  ::wm::UserActivityDetector* user_activity_detector() {
-    return user_activity_detector_.get();
-  }
   VideoDetector* video_detector() {
     return video_detector_.get();
   }

ash/system/chromeos/power/power_event_observer.cc

@@ -50,7 +50,7 @@ void PowerEventObserver::SuspendImminent() {
         RequestLockScreen();
   }
 
-  shell->user_activity_detector()->OnDisplayPowerChanging();
+  wm::UserActivityDetector::Get()->OnDisplayPowerChanging();
   shell->display_configurator()->SuspendDisplays();
 }
 

chrome/browser/chromeos/app_mode/kiosk_mode_idle_app_name_notification.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/app_mode/kiosk_mode_idle_app_name_notification.h"
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
@@ -57,9 +56,10 @@ KioskModeIdleAppNameNotification::KioskModeIdleAppNameNotification()
 }
 
 KioskModeIdleAppNameNotification::~KioskModeIdleAppNameNotification() {
-  if (ash::Shell::HasInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this)) {
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && user_activity_detector->HasObserver(this)) {
+    user_activity_detector->RemoveObserver(this);
     // At this time the DBusThreadManager might already be gone.
     if (chromeos::DBusThreadManager::IsInitialized())
       chromeos::DBusThreadManager::Get()->GetPowerManagerClient(
@@ -98,8 +98,8 @@ void KioskModeIdleAppNameNotification::SuspendDone(
 }
 
 void KioskModeIdleAppNameNotification::Start() {
-  if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this)) {
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!wm::UserActivityDetector::Get()->HasObserver(this)) {
+    wm::UserActivityDetector::Get()->AddObserver(this);
     chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->AddObserver(
         this);
   }

chrome/browser/chromeos/dbus/display_power_service_provider.cc

@@ -57,8 +57,7 @@ void DisplayPowerServiceProvider::SetDisplayPower(
     // we suspend may trigger a mouse move, which would then be incorrectly
     // reported as user activity.  Let the UserActivityDetector
     // know so that it can ignore such events.
-    ash::Shell::GetInstance()->user_activity_detector()->
-        OnDisplayPowerChanging();
+    wm::UserActivityDetector::Get()->OnDisplayPowerChanging();
 
     DisplayPowerState state = static_cast<DisplayPowerState>(int_state);
     ash::Shell::GetInstance()->display_configurator()->SetDisplayPower(

chrome/browser/chromeos/idle_detector.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/idle_detector.h"
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/logging.h"
 #include "ui/wm/core/user_activity_detector.h"
@@ -16,9 +15,10 @@ IdleDetector::IdleDetector(const base::Closure& on_active_callback,
     : active_callback_(on_active_callback), idle_callback_(on_idle_callback) {}
 
 IdleDetector::~IdleDetector() {
-  if (ash::Shell::HasInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && user_activity_detector->HasObserver(this))
+    user_activity_detector->RemoveObserver(this);
 }
 
 void IdleDetector::OnUserActivity(const ui::Event* event) {
@@ -29,8 +29,8 @@ void IdleDetector::OnUserActivity(const ui::Event* event) {
 
 void IdleDetector::Start(const base::TimeDelta& timeout) {
   timeout_ = timeout;
-  if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!wm::UserActivityDetector::Get()->HasObserver(this))
+    wm::UserActivityDetector::Get()->AddObserver(this);
   ResetTimer();
 }
 

chrome/browser/chromeos/kiosk_mode/kiosk_mode_idle_logout.cc

@@ -42,9 +42,10 @@ KioskModeIdleLogout::KioskModeIdleLogout() {
 }
 
 KioskModeIdleLogout::~KioskModeIdleLogout() {
-  if (ash::Shell::HasInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && user_activity_detector->HasObserver(this))
+    user_activity_detector->RemoveObserver(this);
 }
 
 void KioskModeIdleLogout::Setup() {
@@ -74,8 +75,8 @@ void KioskModeIdleLogout::OnUserActivity(const ui::Event* event) {
 }
 
 void KioskModeIdleLogout::Start() {
-  if (!ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!wm::UserActivityDetector::Get()->HasObserver(this))
+    wm::UserActivityDetector::Get()->AddObserver(this);
   ResetTimer();
 }
 

chrome/browser/chromeos/kiosk_mode/kiosk_mode_idle_logout_unittest.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/kiosk_mode/kiosk_mode_idle_logout.h"
 
-#include "ash/shell.h"
 #include "ash/test/ash_test_base.h"
 #include "base/bind.h"
 #include "base/memory/scoped_ptr.h"
@@ -44,8 +43,7 @@ class KioskModeIdleLogoutTest : public ash::test::AshTestBase {
   }
 
   bool UserActivityObserverRegistered() {
-    return ash::Shell::GetInstance()->user_activity_detector()->HasObserver(
-        idle_logout_);
+    return wm::UserActivityDetector::Get()->HasObserver(idle_logout_);
   }
 
   ScopedDeviceSettingsTestHelper device_settings_test_helper_;

chrome/browser/chromeos/kiosk_mode/kiosk_mode_screensaver.cc

@@ -5,7 +5,6 @@
 #include "chrome/browser/chromeos/kiosk_mode/kiosk_mode_screensaver.h"
 
 #include "ash/screensaver/screensaver_view.h"
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/lazy_instance.h"
@@ -199,10 +198,10 @@ KioskModeScreensaver::~KioskModeScreensaver() {
 
   // In case we're shutting down without ever triggering the active
   // notification and/or logging in.
-  if (ash::Shell::GetInstance() &&
-      ash::Shell::GetInstance()->user_activity_detector() &&
-      ash::Shell::GetInstance()->user_activity_detector()->HasObserver(this))
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && user_activity_detector->HasObserver(this))
+    user_activity_detector->RemoveObserver(this);
 }
 
 void KioskModeScreensaver::GetScreensaverCrxPath() {
@@ -252,7 +251,7 @@ void KioskModeScreensaver::SetupScreensaver(
   if (chromeos::LoginState::Get()->IsUserLoggedIn())
     return;
 
-  ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  wm::UserActivityDetector::Get()->AddObserver(this);
 
   ExtensionService* extension_service = GetDefaultExtensionService();
   // Add the extension to the extension service and display the screensaver.
@@ -269,7 +268,7 @@ void KioskModeScreensaver::SetupScreensaver(
 void KioskModeScreensaver::OnUserActivity(const ui::Event* event) {
   // We don't want to handle further user notifications; we'll either login
   // the user and close out or or at least close the screensaver.
-  ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  wm::UserActivityDetector::Get()->RemoveObserver(this);
 
   // Find the retail mode login page.
   if (LoginDisplayHostImpl::default_host()) {

chrome/browser/chromeos/login/screens/user_selection_screen.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/login/screens/user_selection_screen.h"
 
-#include "ash/shell.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/prefs/pref_service.h"
@@ -106,13 +105,9 @@ UserSelectionScreen::UserSelectionScreen() : handler_(NULL) {
 }
 
 UserSelectionScreen::~UserSelectionScreen() {
-#if !defined(USE_ATHENA)
-  // TODO(dpolukhin): crbug.com/408752
-  wm::UserActivityDetector* activity_detector =
-      ash::Shell::GetInstance()->user_activity_detector();
+  wm::UserActivityDetector* activity_detector = wm::UserActivityDetector::Get();
   if (activity_detector->HasObserver(this))
     activity_detector->RemoveObserver(this);
-#endif
 }
 
 // static
@@ -210,13 +205,9 @@ void UserSelectionScreen::Init(const user_manager::UserList& users,
   users_ = users;
   show_guest_ = show_guest;
 
-#if !defined(USE_ATHENA)
-  // TODO(dpolukhin): crbug.com/408752
-  wm::UserActivityDetector* activity_detector =
-      ash::Shell::GetInstance()->user_activity_detector();
+  wm::UserActivityDetector* activity_detector = wm::UserActivityDetector::Get();
   if (!activity_detector->HasObserver(this))
     activity_detector->AddObserver(this);
-#endif
 }
 
 void UserSelectionScreen::OnBeforeUserRemoved(const std::string& username) {

chrome/browser/chromeos/login/ui/webui_login_display.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/login/ui/webui_login_display.h"
 
-#include "ash/shell.h"
 #include "chrome/browser/chromeos/accessibility/accessibility_manager.h"
 #include "chrome/browser/chromeos/login/lock/screen_locker.h"
 #include "chrome/browser/chromeos/login/screens/chrome_user_selection_screen.h"
@@ -35,12 +34,9 @@ namespace chromeos {
 WebUILoginDisplay::~WebUILoginDisplay() {
   if (webui_handler_)
     webui_handler_->ResetSigninScreenHandlerDelegate();
-#if !defined(USE_ATHENA)
-  wm::UserActivityDetector* activity_detector = ash::Shell::GetInstance()->
-    user_activity_detector();
+  wm::UserActivityDetector* activity_detector = wm::UserActivityDetector::Get();
   if (activity_detector->HasObserver(this))
     activity_detector->RemoveObserver(this);
-#endif
 }
 
 // LoginDisplay implementation: ------------------------------------------------
@@ -71,12 +67,9 @@ void WebUILoginDisplay::Init(const user_manager::UserList& users,
   show_users_ = show_users;
   show_new_user_ = show_new_user;
 
-#if !defined(USE_ATHENA)
-  wm::UserActivityDetector* activity_detector = ash::Shell::GetInstance()->
-      user_activity_detector();
+  wm::UserActivityDetector* activity_detector = wm::UserActivityDetector::Get();
   if (!activity_detector->HasObserver(this))
     activity_detector->AddObserver(this);
-#endif
 }
 
 // ---- Common methods

chrome/browser/chromeos/policy/recommendation_restorer.cc

@@ -4,7 +4,6 @@
 
 #include "chrome/browser/chromeos/policy/recommendation_restorer.h"
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
@@ -107,11 +106,14 @@ void RecommendationRestorer::Restore(bool allow_delay,
 
   if (logged_in_) {
     allow_delay = false;
-  } else if (allow_delay && ash::Shell::HasInstance()) {
+  } else if (allow_delay) {
     // Skip the delay if there has been no user input since the browser started.
     const wm::UserActivityDetector* user_activity_detector =
-        ash::Shell::GetInstance()->user_activity_detector();
-    allow_delay = !user_activity_detector->last_activity_time().is_null();
+        wm::UserActivityDetector::Get();
+    if (user_activity_detector &&
+        user_activity_detector->last_activity_time().is_null()) {
+      allow_delay = false;
+    }
   }
 
   if (allow_delay)
@@ -133,12 +135,10 @@ void RecommendationRestorer::StartTimer() {
   // Listen for user activity so that the timer can be reset while the user is
   // active, causing it to fire only when the user remains idle for
   // |kRestoreDelayInMs|.
-  if (ash::Shell::HasInstance()) {
-    wm::UserActivityDetector* user_activity_detector =
-        ash::Shell::GetInstance()->user_activity_detector();
-    if (!user_activity_detector->HasObserver(this))
-      user_activity_detector->AddObserver(this);
-  }
+  wm::UserActivityDetector* user_activity_detector =
+      wm::UserActivityDetector::Get();
+  if (user_activity_detector && !user_activity_detector->HasObserver(this))
+    user_activity_detector->AddObserver(this);
 
   // There should be a separate timer for each pref. However, in the common
   // case of the user changing settings, a single timer is sufficient. This is
@@ -156,8 +156,8 @@ void RecommendationRestorer::StartTimer() {
 
 void RecommendationRestorer::StopTimer() {
   restore_timer_.Stop();
-  if (ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->RemoveObserver(this);
 }
 
 }  // namespace policy

chrome/browser/chromeos/session_length_limiter.cc

@@ -6,7 +6,6 @@
 
 #include <algorithm>
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/location.h"
@@ -98,20 +97,20 @@ SessionLengthLimiter::SessionLengthLimiter(Delegate* delegate,
     UpdateSessionStartTime();
   }
 
-  if (!user_activity_seen_ && ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+  if (!user_activity_seen_ && wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->AddObserver(this);
 }
 
 SessionLengthLimiter::~SessionLengthLimiter() {
-  if (!user_activity_seen_ && ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (!user_activity_seen_ && wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->RemoveObserver(this);
 }
 
 void SessionLengthLimiter::OnUserActivity(const ui::Event* event) {
   if (user_activity_seen_)
     return;
-  if (ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->RemoveObserver(this);
   user_activity_seen_ = true;
 
   PrefService* local_state = g_browser_process->local_state();

chrome/browser/chromeos/system/automatic_reboot_manager.cc

@@ -11,7 +11,6 @@
 #include <algorithm>
 #include <string>
 
-#include "ash/shell.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/callback.h"
@@ -172,8 +171,8 @@ AutomaticRebootManager::AutomaticRebootManager(
   // idle. Start listening for user activity to determine whether the user is
   // idle or not.
   if (!user_manager::UserManager::Get()->IsUserLoggedIn()) {
-    if (ash::Shell::HasInstance())
-      ash::Shell::GetInstance()->user_activity_detector()->AddObserver(this);
+    if (wm::UserActivityDetector::Get())
+      wm::UserActivityDetector::Get()->AddObserver(this);
     notification_registrar_.Add(this, chrome::NOTIFICATION_LOGIN_USER_CHANGED,
         content::NotificationService::AllSources());
     login_screen_idle_timer_.reset(
@@ -202,8 +201,8 @@ AutomaticRebootManager::~AutomaticRebootManager() {
   DBusThreadManager* dbus_thread_manager = DBusThreadManager::Get();
   dbus_thread_manager->GetPowerManagerClient()->RemoveObserver(this);
   dbus_thread_manager->GetUpdateEngineClient()->RemoveObserver(this);
-  if (ash::Shell::HasInstance())
-    ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+  if (wm::UserActivityDetector::Get())
+    wm::UserActivityDetector::Get()->RemoveObserver(this);
 }
 
 void AutomaticRebootManager::AddObserver(
@@ -270,8 +269,8 @@ void AutomaticRebootManager::Observe(
   } else if (type == chrome::NOTIFICATION_LOGIN_USER_CHANGED) {
     // A session is starting. Stop listening for user activity as it no longer
     // is a relevant criterion.
-    if (ash::Shell::HasInstance())
-      ash::Shell::GetInstance()->user_activity_detector()->RemoveObserver(this);
+    if (wm::UserActivityDetector::Get())
+      wm::UserActivityDetector::Get()->RemoveObserver(this);
     notification_registrar_.Remove(
         this, chrome::NOTIFICATION_LOGIN_USER_CHANGED,
         content::NotificationService::AllSources());

chrome/browser/idle_chromeos.cc

@@ -10,14 +10,8 @@
 #include "ui/wm/core/user_activity_detector.h"
 
 void CalculateIdleTime(IdleTimeCallback notify) {
-#if defined(USE_ATHENA)
-  // TODO(oshima): Implement this for athena. crbug.com/408752
-  base::TimeDelta idle_time;
-  NOTIMPLEMENTED();
-#else
   base::TimeDelta idle_time = base::TimeTicks::Now() -
-      ash::Shell::GetInstance()->user_activity_detector()->last_activity_time();
-#endif
+      wm::UserActivityDetector::Get()->last_activity_time();
   notify.Run(static_cast<int>(idle_time.InSeconds()));
 }
 

ui/wm/core/user_activity_detector.cc

@@ -14,6 +14,8 @@ namespace wm {
 
 namespace {
 
+UserActivityDetector* g_instance = nullptr;
+
 // Returns a string describing |event|.
 std::string GetEventDebugString(const ui::Event* event) {
   std::string details = base::StringPrintf(
@@ -44,9 +46,17 @@ const int UserActivityDetector::kNotifyIntervalMs = 200;
 const int UserActivityDetector::kDisplayPowerChangeIgnoreMouseMs = 1000;
 
 UserActivityDetector::UserActivityDetector() {
+  CHECK(!g_instance);
+  g_instance = this;
 }
 
 UserActivityDetector::~UserActivityDetector() {
+  g_instance = nullptr;
+}
+
+// static
+UserActivityDetector* UserActivityDetector::Get() {
+  return g_instance;
 }
 
 bool UserActivityDetector::HasObserver(UserActivityObserver* observer) const {

ui/wm/core/user_activity_detector.h

@@ -29,6 +29,9 @@ class WM_EXPORT UserActivityDetector : public ui::EventHandler {
   UserActivityDetector();
   ~UserActivityDetector() override;
 
+  // Returns the UserActivityDetector instance if one was created.
+  static UserActivityDetector* Get();
+
   base::TimeTicks last_activity_time() const { return last_activity_time_; }
 
   void set_now_for_test(base::TimeTicks now) { now_for_test_ = now; }